Amine-containing materials such as amine-containing analytes, amino acids, DNA, RNA, proteins, cells, tissue, organelles, immunoglobins, or fragments thereof immobilized on a surface can be used in numerous applications. For example, immobilized biological amines can be used for the medical diagnosis of a disease or genetic defect, for biological separations, or for detection of various biomolecules. Immobilization of the amine containing material is typically accomplished by reaction of an amino group with an amine reactive functional group that is covalently attached to the surface of the substrate.
Such amine reactive surfaces can be prepared, for example, by coating onto the surface of a substrate a solution of a polymeric material prepared from an amine reactive monomer such as N-[(meth)acryloxy]succinimide or vinyl azlactone. An amine-containing material can react with the N-acyloxysuccinimide group resulting in displacement of N-hydroxysuccinimide and formation of a carboxamide. An amine-containing material can react with the cyclic azlactone resulting in an opening of the ring structure.
Although polymeric surfaces that include a reactive functional group such as an N-acyloxysuccinimide group or an azlactone group can react readily with primary or secondary amine-containing materials, such reactive functional groups can suffer from a number of disadvantages. For example, many of the reactions with biological amines are conducted in dilute aqueous solutions. Under these conditions, the N-acyloxysuccinimide functional group is known to undergo rapid hydrolysis. This competing reaction can cause incomplete or inefficient immobilization of the amine-containing materials on the substrate.
While azlactone functional groups are more stable to hydrolysis, it is difficult to synthesize an azlactone linked to any polymerizable group other than a vinyl group. This results in polymeric material with the amine reactive functional group directly attached to the polymer backbone. This can make it difficult for the amine containing material to get close enough to the amine reactive group for efficient immobilization.
A need exists for polymeric materials with alternative amine reactive functional groups that can be used as coatings for the immobilization of amine-containing materials and that have good adhesion to a substrate.